Perhaps you should try some spelling variations:
van nhanh » van thanh, van hanh, van khanh
nhanh hai » nhanh thai, thanh hai, nhanh ha
dam thuc » dan thuc, nam thuc, dai thuc
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
ty dang » ky dang, ty hang, ty dong
hieu ve » hieu va, hieu van
hai cua » thai cua, dai cua, hoi cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((ty dang) OR (ty xang)) xa hoi. hieu ve ((dam thuc) or (am thuc)) van nhanh hai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty dang) OR (ty xang)) xa hoi. hieu ve ((dam thuc) OR (am thuc)) van nhanh hai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty dang) OR (ty xang)) xa hoi. hieu ve ((dam thuc) or (am thuc)) van nhanh hai cua viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty dang) OR (ty xang)) xa hoi. hieu ve ((dam thuc) or (am thuc)) van nhanh hai cua viet*.